Stabilizer systems for water-borne vessels

ABSTRACT

A stabilizer system for a ship having one or more hollow closed cylinders or fins projecting from the ship&#39;&#39;s hull into the water stream. Each cylinder or fin is provided with apertures through which water under pressure, supplied by a pump via valves, is directed to produce a variable boundary layer flow of water giving positive or negative lift on the or each cylinder or fin. The valves are operated by a hydraulic actuator in accordance with signals from a gyroscopic sensing mechanism so that the lift produced on each cylinder or fin opposes pitching, rolling and/or yawing motion of the ship.

I United States Patent [151 3,643,617. Holden Feb. 22, 1972 [54]STABILIZER SYSTEMS FOR WATER- 2,925,129 2/1960 Yuan ..416/1 BORNEVESSELS 2,550,752 5/1951 Allan ..l14/126 [72] Inventor: Stanley JosephHolden, Portsmouth, En- 7 V a Q in W l I gland Primary ExaminerTrygve M.Blix 1 1 Assisnw sper Limited fiilfitlfiffifiiffitl [22] Filed: Feb. 24,1970 21 Appl. No.: 13,599 1 ABSTRACT A stabilizer system for a shiphaving one or. more hollow closed cylinders or fins projecting from theships hull into the [301 Foreign Applicamn Pnomy Data water stream. Eachcylinder or fin is provided with apertures Feb. 27, 1969 Great Britain..l0,552/69 through which water under p r pp y a p mp ia valves, isdirected to produce a variable boundary layer flow 52 us. (:1. ..114/1261 l4/66.5 H water giving Pmifi"e negative the cylinder [51] Int Cl B63b39/06 or fin. The valves are operated by a hydraulic actuator inaccordance with signals from a gyroscopic sensing mechanism so [58]Field of Search ..l l4/66.5 H, 2:, that the lift Produced on eachcylinder or fin pp pitching,

/ rolling and/or yawing motion of the ship.

[56] References Cited 16 Claims, 6 Drawing Figures UNITED STATES PATENTS3,472,192 10/1969 Yuan 114/66 5l-l Ma #2 fie PATENTE0FEB22|912 3543.617

SHEET 1 [IF 3 I I L/ l I F2 j /J Inventor STANLEY JOISEPHHOLDENAttorneys PAIENIEUFEBZZIBYZ v 3,643,617

' sum 3 or 3 H/VJ O I I 1 26 L- c Inventor STANLEY JOSEPH HOLDENAttorneys STABILIZER SYSTEMS FOR WATER-HORNE VESSELS BACKGROUND OFINVENTION The invention relates to a stabilizer system for a waterbornevessel.

SUMMARY OF THE INVENTION According to the invention, a stabilizer systemfor a waterborne vessel comprises at least one member projecting intothe water and provided with a variable boundary layer flow of water, theflow of water being controlled by valve means which are actuated inaccordance with signals from vessel attitude-sensing means to produce avariable lift force on the or each member.

DESCRIPTION OF THE INVENTION The invention will now be described, by wayof example only, with reference to the accompanying drawings of which:

FIG. 1 is a plan view of a stabilizer member projecting from the hull ofa ship;

FIG. 2 is a cross section on the line 22 in FIG. 1;

FIG. 3 is a diagrammatic view of automatic control gear for the member,

FIG. 4 is a sectional elevation of a mechanism for retracting the memberinto the ships hull;

FIG. 5 is a sectional elevation of an alternative mechanism forretracting the member into the ships hull; and

FIG. 6 is a plan view of the mechanism shown in FIG. 5.

Referring now to the drawings, a member comprising a hollow cylinder 11with a closed outer end 12 projects from a ships hull 13 into the waterstream shown by the arrows 14 in FIG. 1, produced by the forward motionof the ship. The cylinder II is divided internally into halves I5 and 16by a longitudinal portion 17 which is disposed parallel to the directionof motion of the ship, and water discharge slots 18, 19, 20 and 21 areformed in the cylinder 11, arranged symmetrically two on each side ofthe partition 17. Each slot is so shaped that water is dischargedtherefrom in a rearward direction as nearly tangential to the outersurface of the cylinder 11 as possible. When water under pressure issupplied to the half of the cylinder 11 and discharged from the slots 18and 19, the water stream is modified as shown by the arrows 14a in FIG.2, and lift is induced on the cylinder 11 in the direction shown by thearrow 22 in said figure. Alternatively, by supplying water underpressure to the half 16 of the cylinder 11 and discharging it from theslots and 21, lift is produced in the opposite direction.

Referring to FIG. 3, automatic control gear comprises roll sensing meansin the form of a gyroscopic sensingmechanism 23 which transmits a signalto an electrical control unit 24. Said unit causes a hydraulic circuit25 to actuate water control valves 26 and 27 in such a way that thevalve 26 is open when the valve 27 is closed and vice versa. Water isdrawn in through a forward facing intake 28 on the ship's hull l3, anddelivered by a water pump 29 to the valves 26 and 27.

The hydraulic circuit 25 comprises an oil pump 30, an oil filter 31, arelief valve 32, a solenoid-operated directional valve 33, and ahydraulic actuator comprising a piston 34 slidable in a cylinder 35which actuates the valves 26 and 27 via a linkage 36.

In operation, when the ship rolls in one direction, the gyroscopicsensing mechanism 23 transmits a signal to the control unit 24 whichthen energizes one solenoid of the directional valve 33. This directsoil under pressure from the pump to one side of the piston 34 to movethe linkage 36 and open, say, the valve 26 and close the valve 27, withthe results already described. When the ship rolls in the otherdirection, the opposite effect is produced.

FIG. 4 shows an arrangement whereby the cylinder 11 can be retractedinto the ships hull 13 when not in operation. The cylinder 11 isconnected to a coaxial double-acting hydraulic actuator 37 so as to beslidable in a tube 38 mounted in the hull 13. The water supplied fromthe valves 26 and 27 enters a block 39 secured to the tube 38 and isdirected through telescopic tubes 40 and 41 to the respective halves l5and 16 of the cylinder 1 1.

Referring to the alternative retraction mechanism shown in FIGS. 5 and6, the cylinder 11 is provided near its inner end with hollow trunnions42 and 43 mounted in bearings 44 and 45 in the ships hull 13. A tillerarm 46 is attached to the trunnion 42, and a double-acting hydraulicactuator 47 rotates said arm. When the actuator 47 operates, rotation ofthe arm 46 causes the cylinder 11 to retract pivotally into a recess 48in the ships hull 13. The water supply from the valves 26 and 27 entersthe hollow trunnions 42 and 43 via banjo units 49 and 50 and is directedtherefrom to the respective halves l5 and 16 of the cylinder 11.

Roll stabilization can be achieved by the use of a single cylinder 11,but a larger stabilizing torque is obtained by providing two similarcylinders abeam of each other on opposite sides of the ship, socontrolled by the same automatic control gear that when one is exertinga positive lift the other is exerting a negative lift, that is to sayboth cylinders are acting to turn the ship about its longitudinal axisin the same rollopposing direction.

Combined pitch and roll stabilization can be achieved by providing twopairs of cylinders, the cylinders of each pair being abeam of each otherand the pairs being spaced fore and aft from each other. All thecylinders are controlled by the same automatic control gear, thegyroscopic sensing mechanism 23 of which is capable of sensing bothpitching and rolling motion of the ships hull l3.

Pitch, roll and yaw stabilization can be achieved in a similar manner byproviding two pairs of cylinders, the cylinders of each pair being abeamof each other, the pairs being spaced fore and aft from each other andeach cylinder being mounted at an angle to the horizontal, preferably45, in the ships hull 13. The cylinders are once again controlled by thesame automatic control gear, the gyroscopic sensing mechanism 23 ofwhich is capable of sensing pitching, rolling and yawing motion of theships hull 13. By mounting each cylinder at an angle to the horizontalthe lift produced on each cylinder has not only a vertical component butalso a horizontal component and this horizontal force can be used tocounteract yaw.

In a modification, the or each projecting member is nonretractable.

In another modification, the or each projecting member is notnecessarily of circular cross section but can be a static fin ofsymmetrical cross section which may be retractable but is particularlysuitable in a nonretractable arrangement in order to minimize drag.

' In a further modification, the hydraulic actuator 37 in FIG. 4 isreplaced by a worm and screw drive.

In yet another modification, the partition 17 is dispensed with and theor each projecting member is provided with at east one rearwardlydirected aperture, for the substantially tangential discharge of water,on each side of a plane bisecting the member ans substantially parallelto the direction of motion of the vessel, the same number of aperturesbeing arranged symmetrically on each side of said plane and eachaperture being selectively and individually supplied with water underpressure.

In yet a further modification, the or each member is a static fin whichis symmetrical in cross section nd is provided with at least onerearwardly directed aperture for the discharge of water on each side ofa plane bisecting the member, said plane being substantially parallel tothe direction of motion of the vessel. Each member is divided internallyin halves by a longitudinal partition parallel to said plane oralternatively each aperture is selectively and individually suppliedwith water under pressure.

In still another modification, the boundary layer flow of water isvaried by sucking in water from the exterior of the or each projectingmember through selected portions of its periphery.

The magnitude of the lift produced by the or each projecting member canbe varied by varying the speed of the pump 29 which delivers water underpressure to produce the boundary layer flow of water.

Whatl claim is:

1. A stabilizer system for a water-borne vessel comprising at least onemember projecting into the water which is divided internally into halvesby a longitudinal partition substantially parallel to the direction ofmotion of the vessel, means for providing the member with a boundarylayer flow of water, vessel attitude-sensing means, and valve meanscontrolled by said sensing means for varying said boundary layer flow,said halves ofthe member being symmetrical and each half having at leastone aperture for the substantially tangential discharge of water.

2. A stabilizer system according to claim 1, wherein each aperture isrearwardly directed.

3. A stabilizer system for a water-borne vessel comprising at least onemember which projects into the water and is divided internally intoseparate upper and lower compartments by a longitudinal partition, meansfor providing the member with a boundary layer flow of water via saidcompartments, vessel attitude-sensing means, and valve means controlledby said sensing means and associated with said compartments for varyingsaid boundary layer flow.

4. A stabilizer system according to claim 3, wherein the compartmentsare symmetrical and each compartment has at least one aperture for thesubstantially tangential discharge of water.

S. A stabilizer system according to claim 4, wherein each said apertureis rearwardly directed.

6. A stabilizer system according to claim 3, wherein said valve meanscomprise two valves each adapted to control the flow of water to onecompartment and so connected that when one valve is open the other valveis closed.

7. A stabilizer system according to claim 3, wherein said member isretractable within the hull of the vessel.

8. A stabilizer system according to claim 3, wherein said member is ofcircular cross section.

9. A stabilizer system according to claim 3, wherein said member ismounted at an angle to the horizontal.

10. A stabilizer system for a water-borne vessel comprising at least onemember projecting into thewater, means for providing the member with aboundary layer flow of water via its interior, at least one-rearwardlydirected substantially tangential aperture in the member, for thedischarge of water under pressure from the member, on each side of aplane bisecting the member and substantially parallel to the directionof travel of the vessel, the same number of apertures being arrangedsymmetrically on each side of said plane and each aperture beingselectively and individually supplied with water under pressure, vesselattitude-sensing means, and valve means for controlling said interiorflow of water, said valve means being controlled by said sensing meansand thereby associated with said apertures for varying said boundarylayer 1 flow.

11. A stabilizer system according to claim 10, wherein the member isretractable.

12. A stabilizer system according to claim 10, wherein the member is ofcircular cross section.

13. A stabilizer system according to claim 10, wherein the member ismounted at an angle to the horizontal.

14. A stabilizer system for a water-borne vessel comprising a hollowstabilizer member adapted to project from the hull of the vessel intothe water, means separating the interior of said member into upper andlower compartments, means providing rearwardly directed water dischargeslots in said member, at least one slot for each compartment, meansincluding valve means for selectively introducing water into one or theother of said compartments for discharge through said slots, and vesselattitude-sensing means operatively connected to control said valvemeans, said slots being so constructed and arranged as to modifyboundary layer flow of water at said member to produce a variable liftforce at said member.

15. The stabilizer system defined in claim 14, wherein said member iscylindrical with its axis normal to the vessel and the respective slotsdischarge water substantially tangentially upwardly and downwardly withrespect to said member.

16. The stabilizer system defined in claim 14, wherein the surface ofsaid member is curved adjacent the discharge ends of said slots and saidslots are oppositely inclined relative to the direction of movement ofsaid vessel.

1. A stabilizer system for a water-borne vessel comprising at least onemember projecting into the water which is divided internally into halvesby a longitudinal partition substantially parallel to the direction ofmotion of the vessel, means for providing the member with a boundarylayer flow of water, vessel attitude-sensing means, and valve meanscontrolled by said sensing means for varying said boundary layer flow,said halves of the member being symmetrical and each half having atleast one aperture for the substantially tangential discharge of water.2. A stabilizer system according to claim 1, wherein each aperture isrearwardly directed.
 3. A stabilizer system for a water-borne vesselcomprising at least one member which projects into the water and isdivided internally into separate upper and lower compartments by alongitudinal partition, means for providing the member with a boundarylayer flow of water via said compartments, vessel attitude-sensingmeans, and valve means controlled by said sensing means and associatedwith said compartments for varying said boundary layer flow.
 4. Astabilizer system according to claim 3, wherein the compartments aresymmetrical and each compartment has at least one aperture for thesubstantially tangential discharge of water.
 5. A stabilizer systemaccording to claim 4, wherein each said aperture is rearwardly directed.6. A stabilizer system according to claim 3, wherein said valve meanscomprise two valves each adapted to control the flow of water to onecompartment and so connected that when one valve is open the other valveis closed.
 7. A stabilizer system according to claim 3, wherein saidmember is retractable within the hull of the vessel.
 8. A stabilizersystem according to claim 3, wherein said member is of circular crosssection.
 9. A stabilizer system according to claim 3, wherein saidmember is mounted at an angle to the horizontal.
 10. A stabilizer systemfor a water-borne vessel comprising at least one member projecting intothe water, means for providing the member with a boundary layer flow ofwater via its interior, at least one rearwardly directed substantiallytangential aperture in the member, for the discharge of water underpressure from the member, on each side of a plane bisecting the memberand substantially parallel to the direction of travel of the vessel, thesame number of apertures being arranged symmetrically on each side ofsaid plane and each aperture being selectively and individually suppliedwith water under pressure, vessel attitude-sensing means, and valvemeans for controlling said interior flow of water, said valve meansbeing controlled by said sensing means and thereby associated with saidapertures for varying said boundary layer flow.
 11. A stabilizer systemaccording to claim 10, wherein the membEr is retractable.
 12. Astabilizer system according to claim 10, wherein the member is ofcircular cross section.
 13. A stabilizer system according to claim 10,wherein the member is mounted at an angle to the horizontal.
 14. Astabilizer system for a water-borne vessel comprising a hollowstabilizer member adapted to project from the hull of the vessel intothe water, means separating the interior of said member into upper andlower compartments, means providing rearwardly directed water dischargeslots in said member, at least one slot for each compartment, meansincluding valve means for selectively introducing water into one or theother of said compartments for discharge through said slots, and vesselattitude-sensing means operatively connected to control said valvemeans, said slots being so constructed and arranged as to modifyboundary layer flow of water at said member to produce a variable liftforce at said member.
 15. The stabilizer system defined in claim 14,wherein said member is cylindrical with its axis normal to the vesseland the respective slots discharge water substantially tangentiallyupwardly and downwardly with respect to said member.
 16. The stabilizersystem defined in claim 14, wherein the surface of said member is curvedadjacent the discharge ends of said slots and said slots are oppositelyinclined relative to the direction of movement of said vessel.